Asian-Americans in California overwhelmingly oppose a ballot measure that would ban gay marriage in the state, according to a ground-breaking survey released today.

The poll found that 57 percent of Asian-Americans likely to vote in the Nov. 4 election oppose Proposition 8, which would reverse last spring’s California Supreme Court ruling that gave gays and lesbians the right to marry. Only 32 percent planned to vote for the measure, with 11 percent undecided.

The California survey, part of a larger national poll released last week, was conducted by researchers at the University of California-Berkeley, UC-Riverside, the University of California and Rutgers University.

The data released today was strictly from California, where one of three Asian-Americans live.

About 1,100 Asian-Americans in the state were interviewed by telephone in eight languages between Aug. 18 and Sept. 26. The survey was the largest scientific poll of Asian-American voters ever done — both nationally and in California.

The National Asian-American Survey also showed that Asian-Americans support Democrat Barack Obama over Republican candidate John McCain by a substantial margin. Nationally, Obama was backed by 41 percent of Asian-American voters and McCain was supported by 24 percent, with 34 percent undecided. In California, the figures were almost identical: 42 percent for Obama, 24 percent for McCain and 33 percent undecided.

In some ways, the lopsided opinion of Proposition 8 was surprising because many Asian-Americans have traditionally been less tolerant of homosexuality. One big reason: Many are emigrants from countries where homosexuality is less tolerated.

Although Asian literature is sprinkled with centuries-old allusions to men having sex with men, or women having sex with women, many Asian societies tend to ignore homosexuality or even deny that it exists — although those attitudes are beginning to change in countries such as Vietnam and China that are rapidly being Westernized.

Experts in Asian-American voting trends attribute the lopsided opinion of Proposition 8 to the ability gay-marriage proponents to frame it as a major civil rights issue.

“The measure certainly has civil rights overtones to it,” said Karthick Ramakrishnan, an associate political science professor at the University of California-Riverside who is a member of the survey’s research team. Asian-Americans, he and other political scientists note, have historically been discriminated against and even, in the case of Japanese-Americans during World War II, thrown into internment camps. So Asian-Americans tend to be more sensitive than other Americans to laws that exclude certain groups, Ramakrishnan said.

“In the ’80s and ’90s,” he said, most Asian-Americans considered homosexuality “more of an issue of fundamental morality.”

Many opponents of Proposition 8 — the only California ballot measure included in the voter survey — say the results don’t surprise them.

“If there is one community that is extraordinarily sensitive to the dangers of the government treating one group differently than another, it would be the Asian-American community,” said Steve Smith, manager of the statewide campaign opposing Proposition 8.

In September 2007, proponents of same-sex marriage point out, a coalition of 60 Asian-American organizations filed a legal brief in support of marriage rights for gay and lesbian couples.

Bill Tam of San Francisco, a Chinese-American who is leading the outreach effort in the Asian-American community to pass Proposition 8, conceded that proponents face a tough battle convincing the community to vote for the measure.

Gay marriage supporters “have very cleverly portrayed homosexuals as a kind of minority,” Tam said. “They’ve been very effective in portraying it as a civil rights issue, and this is very much a concern for us.”

But he said he hopes ads in Asian-American media outlets will cut into support for the measure, as they appear to be doing in the mainstream voter population since Proposition 8 supporters began an intense advertising campaign at the end of September. The ads maintain that allowing gays to legally marry will result in schools teaching children about same-sex marriage.

The latest polling shows the two sides on Proposition 8 running neck and neck.

“We hope to convince Asian-Americans that gay marriage will encourage more children to experiment with the gay lifestyle and that the lifestyle comes with all kinds of disease,” he said.

In the California presidential primary, Asian-American Democratic voters supported Hillary Clinton over Barack Obama by a small margin. Sixty-two percent of former Clinton supporters plan to vote for Obama. Eight percent of them plan to vote for McCain, and 26 percent are undecided.

Preferences for the presidential candidates vary widely by national origin. Support for McCain is highest among Vietnamese likely voters, with 53 percent planning to vote for the Republican candidate. In contrast, a majority of Indians (62 percent) and Japanese Americans (53 percent) plan to vote for Obama. Chinese and Filipino likely voters favor Obama over McCain, but a large share remain undecided. Korean likely voters favor Obama (34 percent) only slightly over McCain (31 percent).

Almost half of Asian-American citizens in California say they depend primarily on Asian-language television and newspapers to stay informed on politics.

Asian-American participation in the politics of their home countries is not a deterrent to involvement in U.S. politics. Indeed, those involved in politics in their homelands are more likely to vote in the United States than those who do not (65 percent versus 50 percent).

Because of higher citizenship rates among Asian-Americans in California, the proportion of likely voters among all Asian-American adults is higher in the state (50 percent) than in the rest of the country (43 percent.)

The margin of error for the California survey was plus or minus 3 percentage points.

Otto Warmbier was arrested in January 2016 at the end of a brief tourist visit to North Korea. He had been medically evacuated and was being treated at the University of Cincinnati Medical Center when he died at age 22.